Galectin-8 promotes migration and proliferation and prevents apoptosis in U87 glioblastoma cells

Biological research: BR

s¹  Alfonso Gonzá²  Claudia Metz²  Ronan Shaughnessy³  lez⁴  Remziye Dö⁴  Elizabeth Riquelme⁵  Claudia Oyanadel⁶  Priscilla Corté⁷  Catalina Grabowski⁷  Christopher Holmes⁸  Andrea Soza⁹  ger⁹ 

[1] Centro de Envejecimiento y RegeneracióDepartamento de Inmunología Celular y Molecular, Facultad de Ciencias Biolóa Clía, Facultad de Medicina, Pontificia Universidad Catógicas, Pontificia Universidad Católica de Chile, Santiago, Chile;n, Departamento de Biologínica y Reumatologí

关键词: Galectin-8;    Glioblastoma;    Cancer;    Cell cycle;    Apoptosis;    Proliferation;    Migration;   

DOI  :  10.1186/s40659-016-0091-6

学科分类：生物科学（综合）

来源: BioMed Central

【 摘 要 】

Glioblastoma is one of the most aggressive cancers of the brain. Malignant traits of glioblastoma cells include elevated migration, proliferation and survival capabilities. Galectins are unconventionally secreted glycan-binding proteins that modulate processes of cell adhesion, migration, proliferation and apoptosis by interacting with beta-galactosides of cell surface glycoproteins and the extracellular matrix. Galectin-8 is one of the galectins highly expressed in glioblastoma cells. It has a unique selectivity for terminally sialylated glycans recently found enhanced in these highly malignant cells. A previous study in glioblastoma cell lines reported that Gal-8 coating a plastic surface stimulates two-dimensional motility. Because in other cells Gal-8 arrests proliferation and induces apoptosis, here we extend its study by analyzing all of these processes in a U87 glioblastoma cell model. We used immunoblot and RT-PCR for Gal-8 expression analysis, recombinant Gal-8 produced in a bacteria system for Gal-8 treatment of the cells, and shRNA in lentivirus transduction for Gal-8 silencing. Cell migration as assessed in transwell filters. Cell proliferation, cell cycle and apoptosis were analyzed by FACS. Gal-8 as a soluble stimulus triggered chemotactic migration of U87 cells across the polycarbonate filter of transwell chambers, almost as intensively as fetal bovine serum. Unexpectedly, Gal-8 also enhanced U87 cell growth. Co-incubation of Gal-8 with lactose, which blocks galectin–glycan interactions, abrogated both effects. Immunoblot showed Gal-8 in conditioned media reflecting its secretion. U87 cells transduced with silencing shRNA in a lentiviral vector expressed and secreted 30–40 % of their normal Gal-8 levels. These cells maintained their migratory capabilities, but decreased their proliferation rate and underwent higher levels of apoptosis, as revealed by flow cytometry analysis of cell cycle, CFSE and activated caspase-3 staining. Proliferation seemed to be more sensitive than migration to Gal-8 expression levels. Gal-8, either secreted or exogenously enriched in the media, and acting through extracellular glycan interactions, constitutes a strong stimulus of directional migration in glioblastoma U87 cells and for the first time emerges as a factor that promotes proliferation and prevents apoptosis in cancerous cells. These properties could potentially contribute to the exaggerated malignancy of glioblastoma cells.

【 授权许可】

CC BY